Foam-producing device for fire extinguishing purposes



. Oct. 15, 1940. J. MULLER FOAM-PRODUCING DEVICE FOR FIRE EKTINGUISHINGPURPOSES Filed May 2, 1939 n. m m

lnrerlfar-i J Mueller fective Patented Oct. 15, 1940 UNITED STATESFOAM-PRODUCING DEVICE FOR FIRE EXTINGUISHING PURPOSES Josef Miiller,Bergisch-Gladbach, Germany Application May 2, 1939, Serial No. 271,333In Germany May 5, 1938 4 Claims.

In the known devices for producing fire-extinguishing foam the foam isformed by conveying to the mixture as it emerges from nozzles airthrough the injector action of the nozzles. The air supplied in this waycan however not open up and permeate the jet of liquid in an entirelyuniform manner. The range of the jet of foam produced with the hithertoknown devices is also far from satisfactory.

In contradistinction to such devices the invention proposes to supply tothe mixture emerging through outflow openings into the jet tube air fromthe outside under pressure. By this mea s in the first place acompletely uniform and efintermixture is brought about and through thepressure action of the supplied air a jet of foam, having a long range,is produced.

According to the invention the outflow openings may produce inwardly oroutwardly diverging jets and the stream of air under pressure canimpinge on the jet of mixture produced in this way and thereby assistthe formation of foam in a particularly effective manner.

According to the invention, for producing outwardiy diverging jets ofmixture, which therefore on leaving the outlet openings impinge againstthe inside of the wall of a jet tube, an adjustable cone may be used,which lies in the outflow opening of the jet of mixture. This cone will.then have a double duty to perform. In the first place it divides up theflow of mixture uniformly and conveys it, as already stated, against theinside walls of the jet tube, where it already produces foaming byfriction, and in the second place through its axial displacement thesize of the annular opening is changed with respect to the outlet end ofthe supplying tube which conveys the jet ofmixture into the jet tube,whereby the quantity of foam delivered is regulable. a

The accompanying drawing illustrates the arrangement according to theinvention by two constructional examples, Figs. 1 and 2 showing thefirst constructional example and Fig. 3 an example with the conereferred to. Figs. 1 and 3 show central longitudinal sections and Fig. 2the upper part of the appliance in elevation and the lower part insection.

In the example according to Figs. 1 and 2 the mixture consisting ofwater and a foam-forming agent is fed to the jet tube a under pressurefrom the connecting branch (2 through the tube b.

At the inner end of the latter tube a distributing body It is mounted insuch a manner that the jet of mixture is separated into part streamswhich under the openings i in the casing, so that, when 10 the turbinewheel is rotating, air is sucked in from both sides and is deliveredunder pressure to the jet tube a. In this way the air under pressurepasses through the finely dividedmixture, causing it to foam in anextremely efiil5 cient manner. Through the increase in pressure thusproduced the jet of foam is projected-to a great distance. x

In the constructional example shown in Fig- 3 the jet of mixture isthrown by a cone built into the inner end of the tube b directly againstthe inside of the wall of the jet tube a. The said cone Z is mounted ona rod m which is provided with a few convolutions of a screw thread, forwhich a female thread is provided at n. The outer end of the rod m isprovided with a handle o. By turning the handle 0 in one direction orthe otherv the annular gap surrounding the cone is reduced orenlarged,whereby the quantity of foam to be produced can be regulated, In 80place of air some other gas may be supplied under pressure.

What I claim is:

1. .A foam-producing device comprising a conical tube having the smallend open and the large end closed, a cylindrical tube passing throughthe closed end of the conical tube, an enlargement on the conical tube,spaced walls arranged in said enlargement, a shaft rotatably mounted insaid walls, a turbine wheel mounted on said shaft be- 5 tween saidwalls, a nozzle formed in the wall of said cylindrical tube and arrangedto direct a part of the medium passing through the cylindrical tubeagainst said turbine wheel, a propeller wheel on said shaft at the outerside of each wall, air inlets in the enlargement to admit air into the,interior of the conical tube;

2. A foam-producing devicecomprising a conical tube having the small endopen and the large end closed, a cylindrical tube passing through theclosed end of the conical tube, an enlargement on the conical tube,spaced walls arranged in said enlargement, a shaft rotatably mounted insaid walls, a turbine wheel mounted on said shaft between said walls, anozzle formed in the wall 2 of said cylindrical tube and arranged todirect a part of the medium passing through the cylindrical tube againstsaid turbine wheel, a propel--- ler wheel on said shaftat the outer sideof each wall, air inlets in the enlargement to admit air into theinterior of the conical tube, at the inner end of the cylindrical tube.I

3. A foam-producing device comprising a conical tube having the smallend open and the large air into the interior of the conical tube, and aconical member for directing the medium passing through the inner end ofthe cylindrical tube across the air delivered by said propellers.

4; A foam-producing device comprising a conical tube having the smallend open and the large end closed, a cylindrical tube passing throughthe closed end of the conical tube, an enlargement on the conical tube,spaced walls arranged in said enlargement, a shaft rotatably mounted insaid walls, a turbine wheel mounted on said shaft between said walls, anozzle formed in the wall of said cylindrical tube. and arranged to di-Ill rect a part of the medium passing through the" cylindrical tubeagainst said turbine wheel, a propeller wheel on said shaft at the'outer side of each wall, air inlets in the enlargement to admit airinto the interior of the conical tube, a, conical member for directingthe medium passing through the inner end of the cylindrical tube acrossthe air delivered by said propellers, and means for adjusting saidconical member axially of the cylindrical tube.

JOSEF MULLER.-

